"Dar es Salaam Marine Reserve The Dar es Salaam Marine Reserve System (DMRS) is a group of marine wildlife reserves in Tanzania, situated off the coast of Dar es Salaam Region. The reserve system consists of nine uninhabited islands, four north of Dar es Salaam (Bongoyo, Mbudya, Pangavini and Fungu Yasini) and five south of the city (Inner and Outer Makatumbe, Inner and Outer Sinda and Kendwa Island). It provides protection for several important tropical ecosystems; coral reefs, mangroves and seagrass beds. Management of the reserve is governed by the Tanzanian Board of Trustees of Marine Parks and Reserves which"
"corals (only six of which contribute to reef formation). Marine primary producers — plants and microscopic organisms in the plankton — are widespread and very essential for the ecosystem. It has been estimated that half of the world's oxygen is produced by phytoplankton. About 45 percent of the sea's primary production of living material is contributed by diatoms. Much larger algae, commonly known as seaweeds, are important locally; ""Sargassum"" forms floating drifts, while kelp form seabed forests. Flowering plants in the form of seagrasses grow in ""meadows"" in sandy shallows, mangroves line the coast in tropical and subtropical regions and"
"Coral island A coral island is a type of island formed from coral detritus and associated organic material. They occur in tropical and sub-tropical areas, typically as part of coral reefs which have grown to cover a far larger area under the sea. Coral reefs are some of the oldest ecosystems on the planet. Over geological time forming massive reefs made of limestone. The reef environment supports more plant and animal species than any other habitat. Coral reefs are vital for life for multiple aspects some of which include structure, ecology, and nutrient cycles which all support biodiversity in the"
"are small with low elevation above sea level. Thus they are at threat from storms and rising sea levels. Coral island A coral island is a type of island formed from coral detritus and associated organic material. They occur in tropical and sub-tropical areas, typically as part of coral reefs which have grown to cover a far larger area under the sea. Coral reefs are some of the oldest ecosystems on the planet. Over geological time forming massive reefs made of limestone. The reef environment supports more plant and animal species than any other habitat. Coral reefs are vital for"
"reefs. The reefs build massive calcareous skeletons that serve as homes for animals from fish hiding inside the crooks and crannies of the reef and barnacles attaching themselves directly to the coral’s structure. The reef’s structure also helps with plants that need the sun to photosynthesize; by lifting the plants to the ocean’s surface where the sunlight can penetrate the water. The structure of the reef also creates a calm zone in the ocean providing a great place for fish and plant species to thrive. Over geological time the reefs reach the surface and can become a coral island, where"
"effects of food chains in coral reef ecosystems and may provide yet another key to unlocking the paradox. Cyanobacteria provide soluble nitrates via nitrogen fixation. Coral reefs often depend on surrounding habitats, such as seagrass meadows and mangrove forests, for nutrients. Seagrass and mangroves supply dead plants and animals that are rich in nitrogen and serve to feed fish and animals from the reef by supplying wood and vegetation. Reefs, in turn, protect mangroves and seagrass from waves and produce sediment in which the mangroves and seagrass can root. Coral reefs form some of the world's most productive ecosystems, providing"
"that build reefs. In the early Cambrian period, ""Archaeocyatha"" sponges were the world's first reef-building organisms, and sponges were the only reef-builders until the Ordovician. Sclerosponges still assist corals building modern reefs, but like coralline algae are much slower-growing than corals and their contribution is (usually) minor. In the northern Pacific Ocean cloud sponges still create deep-water mineral-structures without corals, although the structures are not recognizable from the surface like tropical reefs. They are the only extant organisms known to build reef-like structures in cold water. In ""The Structure and Distribution of Coral Reefs"", published in 1842, Darwin described how"
"of the world's marine ecosystems. The coral reef ecosystem provides habitat to over 9 million species covering approximately one fourth of marine life. Its three dimensional structure provides hiding places for fish, shrimp and clams. Coral itself is consumed by species such as parrotfish. It provides a hunting ground for predators. Coral reefs houses plants and animals that produce chemical compounds that have found use in human medicines. As early as the 14th century, the medicinal properties of coral reef dwelling species were utilized. Antiviral extracts and tonics continue to be studied and toxic compounds such as neurotoxins discovered in"
"and rhizomes stabilize the seabed. Their importance to associated species is mainly due to provision of shelter (through their three-dimensional structure in the water column), and due to their extraordinarily high rate of primary production. As a result, seagrasses provide coastal zones with ecosystem services, such as fishing grounds, wave protection, oxygen production and protection against coastal erosion. Seagrass meadows account for 15% of the ocean’s total carbon storage. Reefs comprise some of the densest and most diverse habitats in the world. The best-known types of reefs are tropical coral reefs which exist in most tropical waters; however, reefs can"
"of the reef structure. The teeth grow continuously, replacing material worn away by feeding. Their pharyngeal teeth grind up the coral and rocks the fish ingest during feeding. After they digest the edible portions from the rock, they excrete it as sand, helping create small islands and the sandy beaches. The humphead parrotfish can produce of sand each year. Or, very averagely (as there are so many variables i.e. size/species/location/depth etc.), almost per parrotfish per day. While feeding, parrotfish must be cognizant of predation by one of their main predators, the lemon shark. On Caribbean coral reefs, parrotfish are important"
"Coral reefs are the result of mutualisms between coral organisms and various types of algae which live inside them. Most land plants and land ecosystems rely on mutualisms between the plants, which fix carbon from the air, and mycorrhyzal fungi, which help in extracting water and minerals from the ground. An example of mutualism is the relationship between the ocellaris clownfish that dwell among the tentacles of Ritteri sea anemones. The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators. A special mucus on the clownfish"
"corals as they create the framework for the habitat most coral-reef organisms depend on. Some ecosystem engineers such as coral have help maintaining their environment. Parrotfish often help maintain coral reefs as they feed on macroalgae that competes with the coral. As this relationship is mutually beneficial, a positive feedback cycle is formed between the two organisms, making them both responsible for creating and maintaining coral reef ecosystems. Ecosystem engineer An ecosystem engineer is any organism that creates, significantly modifies, maintains or destroys a habitat. These organisms can have a large impact on the species richness and landscape-level heterogeneity of"
"water—and to riverine influences—such as flows of fresh water and sediment. The shifting flows of both sea water and fresh water provide high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world. Reefs comprise some of the densest and most diverse habitats in the world. The best-known types of reefs are tropical coral reefs which exist in most tropical waters; however, reefs can also exist in cold water. Reefs are built up by corals and other calcium-depositing animals, usually on top of a rocky outcrop on the"
"Coral reefs are the largest structures created by living organisms, and contain abundant and highly complex microbial communities. A coral ""head"" is a colony of genetically identical polyps, which secrete an exoskeleton near the base. Depending on the species, the exoskeleton may be hard, based on calcium carbonate, or soft and proteinaceous. Over many generations, the colony creates a large skeleton that is characteristic of the species. Diverse forms of life take up residence in a coral colony, including photosynthetic algae such as ""Symbiodinium"", as well as a wide range of bacteria including nitrogen fixers, and chitin decomposers, all of"
"the world, but they are fragile ecosystems. When tropical waters become unusually warm for extended periods of time, microscopic plants called zooxanthellae, which are symbiotic partners living within the coral polyp tissues, die off. These plants provide food for the corals, and give them their color. The result of the death and dispersal of these tiny plants is called coral bleaching, and can lead to the devastation of large areas of reef. Over 42% of corals are completely bleached and 95% are experiencing some type of whitening. Historically the Caribbean is thought to contain 14% of the world's coral reefs."
"Coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Coral belongs to the class ""Anthozoa"" in the animal phylum ""Cnidaria"", which includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons that support and protect the coral. Most reefs grow best in warm, shallow, clear, sunny and agitated water. Often called ""rainforests of the sea"", shallow coral reefs form some of Earth's most diverse ecosystems. They occupy"
"middle levels of the food chain and never reaches the larger species that are of interest to fishermen. Tourism centered on reefs provides much of the income of some tropical islands, attracting photographers, divers and sports fishermen. However, human activities damage reefs in several ways: mining for construction materials; pollution, including large influxes of fresh water from storm drains; commercial fishing, including the use of dynamite to stun fish and the capture of young fish for aquariums; and tourist damage caused by boat anchors and the cumulative effect of walking on the reefs. Coral, mainly from the Pacific Ocean has"
"in kaleidoscopes of colours and shapes. Algae are primary producers, which means they are plants synthesising food directly from solar energy and carbon dioxide and other simple nutrient molecules. Without algae, everything on the reef would die. One important algal group, the bottom dwelling (benthic) algae, grows over dead coral and other inert surfaces, and provides grazing fields for herbivores such as parrotfish. Parrotfish are named for their parrot-like beaks and bright colours. They are large herbivores that graze on the algae that grows on hard dead corals. Equipped with two pairs of crushing jaws and their beaks, they pulverize"
"bleaching of coral on the Great Barrier Reef killed between 29 and 50 percent of the reef's coral. In 2017, the bleaching extended into the central region of the reef. The average interval between bleaching events has halved between 1980 and 2016. The corals that form the great reef ecosystems of tropical seas depend upon a symbiotic relationship with algae-like single-celled flagellate protozoa called zooxanthellae that live within their tissues and give the coral its coloration. The zooxanthellae provide the coral with nutrients through photosynthesis, a crucial factor in the clear and nutrient-poor tropical waters. In exchange, the coral provide"
"Reef A reef is a bar of rock, sand, coral or similar material, lying beneath the surface of water. Many reefs result from abiotic processes (i.e. deposition of sand, wave erosion planing down rock outcrops, and other natural processes), but the best known reefs are the coral reefs of tropical waters developed through biotic processes dominated by corals and coralline algae. Artificial reefs (e.g. shipwrecks) sometimes have a role in enhancing the physical complexity of featureless sand bottoms, in order to attract a diverse assemblage of organisms, especially algae, and fish. Earth's largest and most famous reef is the Great"
"fish; for example clown fish live among the tentacles of sea anemones, and each partner protects the other against predators. Coral reefs form some of the world's most productive ecosystems. Common coral reef cnidarians include both Anthozoans (hard corals, octocorals, anemones) and Hydrozoans (fire corals, lace corals). The endosymbiotic algae of many cnidarian species are very effective primary producers, in other words converters of inorganic chemicals into organic ones that other organisms can use, and their coral hosts use these organic chemicals very efficiently. In addition, reefs provide complex and varied habitats that support a wide range of other organisms."
"some sponges. Reefs are always built by the combined efforts of these different phyla, with different organisms leading reef-building in different geological periods. Coralline algae are important contributors to reef structure. Although their mineral deposition-rates are much slower than corals, they are more tolerant of rough wave-action, and so help to create a protective crust over those parts of the reef subjected to the greatest forces by waves, such as the reef front facing the open ocean. They also strengthen the reef structure by depositing limestone in sheets over the reef surface. ""Sclerosponge"" is the descriptive name for all ""Porifera"""
"of the coral-forming marine invertebrates, where they accelerate host-cell metabolism by generating sugar and oxygen immediately available through photosynthesis using incident light and the carbon dioxide produced by the host. Reef-building stony corals (hermatypic corals) require endosymbiotic algae from the genus ""Symbiodinium"" to be in a healthy condition. The loss of ""Symbiodinium"" from the host is known as coral bleaching, a condition which leads to the deterioration of a reef. Endosymbiontic green algae live close to the surface of some sponges, for example, breadcrumb sponges (""Halichondria panicea""). The alga is thus protected from predators; the sponge is provided with oxygen"
"ecosystem in the world. Its reefs, almost 3000 in total, represent about 10 per cent of all the coral reef areas in the world. It supports an amazing variety of biodiversity, providing a home to thousands of coral and other invertebrate species, bony fish, sharks, rays, marine mammals, marine turtles, sea snakes, as well as algae and other marine plants. The Great Barrier Reef Marine Park Authority (GBRMPA) is responsible for the care and protection of the Great Barrier Reef Marine Park. It uses a range of tools to manage the marine park including Acts and Regulations, zoning plan, plans"
"predator fish eating smaller forage fish that eat yet smaller zooplankton and so on. However, all food webs eventually depend on plants, which are the primary producers. Coral reefs typically produce 5–10 grams of carbon per square meter per day (gC·m·day) biomass. One reason for the unusual clarity of tropical waters is their nutrient deficiency and drifting plankton. Further, the sun shines year-round in the tropics, warming the surface layer, making it less dense than subsurface layers. The warmer water is separated from deeper, cooler water by a stable thermocline, where the temperature makes a rapid change. This keeps the"
"infer a region's paleoclimate. Coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Coral belongs to the class ""Anthozoa"" in the animal phylum ""Cnidaria"", which includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons that support and protect the coral. Most reefs grow best in warm, shallow, clear, sunny and agitated water. Often called ""rainforests of the sea"", shallow coral reefs form some of Earth's most"
"symbionts provide the coral with food in exchange for protection. If the waters warm or become too acidic, the symbionts are expelled, the coral bleaches and if conditions persist the coral will die. This in turn leads to the collapse of the entire reef ecosystem. Marine invertebrates are the hosts of a wide spectrum of bioactive metabolites, which have vast potential as drugs and research tools. In many cases, microbes aid in or are responsible for marine invertebrates natural products. Certain marine microbes can provide insight into the biosynthesis mechanisms of natural products, which in turn could solve the current"
"of the Corallinales, reef-building corals, and other living organisms including plants, such as mangroves and animals such as shelled molluscs. The coralline red algae are major members of coral reef communities, cementing the corals together with their crusts. Among the brown algae, the order Ralfsiales comprises two families of crustose algae. Many lichens grow close to the surface of rocks, tree trunks, and other substrata, and are referred to as crustose lichens. Crustose organisms can be detrimental to engineered structures when found on buildings, coastal structures, and ships. There are different types of Crustose lichens, including endolithic, endophloidic and leprose."
"the Caribbean region. This resulted in both affected species being listed as threatened under the US Endangered Species Act and as critically endangered on the IUCN Red List. The decline in these corals has a lasting effect on both humans and the environment. Coral reefs protect coastlines from ocean currents, waves, and storms, and the death of these corals only increases the loss of coastlines in affected regions. Elkhorn and staghorn corals are two of the major reef-building corals, the foundation on which the rest of the coral reef is formed. Its loss means the loss of a habitat for"
"built reefs. Other groups, such as the Bryozoa have been important interstitial organisms, living between the framework builders. The corals which build reefs today, the Scleractinia, arose after the Permian–Triassic extinction event that wiped out the earlier rugose corals (as well as many other groups), and became increasingly important reef builders throughout the Mesozoic Era. They may have arisen from a rugose coral ancestor. Rugose corals built their skeletons of calcite and have a different symmetry from that of the scleractinian corals, whose skeletons are aragonite. However, there are some unusual examples of well-preserved aragonitic rugose corals in the late"
"less than 0.1% of the world's ocean area, about half the area of France, yet they provide a home for at least 25% of all marine species, including fish, mollusks, worms, crustaceans, echinoderms, sponges, tunicates and other cnidarians. Coral reefs flourish in ocean waters that provide few nutrients. They are most commonly found at shallow depths in tropical waters, but deep water and cold water coral reefs exist on smaller scales in other areas. Coral reefs deliver ecosystem services for tourism, fisheries and shoreline protection. The annual global economic value of coral reefs is estimated between US$30–375 billion. Coral reefs"
"need sunlight for photosynthesis, which powers carbon fixation, so they are found only relatively near the surface, but they also need nutrients. Phytoplankton rapidly use nutrients in the surface waters, and in the tropics, these nutrients are not usually replaced because of the thermocline. Around coral reefs, lagoons fill in with material eroded from the reef and the island. They become havens for marine life, providing protection from waves and storms. Most importantly, reefs recycle nutrients, which happens much less in the open ocean. In coral reefs and lagoons, producers include phytoplankton, as well as seaweed and coralline algae, especially"
"grow into an atoll with a shallow lagoon in the middle. The lagoon can then undergo accretion and create an island completely made of carbonate materials.The process is later enhanced with the remains of plant life which grows on the island. Coral is important for biodiversity and the growth of fish populations, so maintaining coral reefs is important. Coral reefs are threatened by numerous anthropogenic impacts, some of which have already had major effects worldwide. Reefs grow in shallow, warm, nutrient poor waters where they are not out competed by phytoplanktons. By adding fertilizers into the water runoff phytoplankton populations"